[chrome] [alpha4] card-columns unstable behaviour

[adriano-tirloni]

I am working with rails gem 'bootstrap', '4.0.0.alpha3.1' after updating to gem 'bootstrap', '4.0.0.alpha4' card-columns became unstable.

A static page would break a card in the middle (img from text like in the Pen below) and start do blink between the correct card position versus this broken one.

I'm using chrome lastest build.

BS4-alpha3.1 Pen:
(http://codepen.io/dritir/pen/gwBxgK)

BS4-alpha4 Pen:
(http://codepen.io/dritir/pen/QKkrGP)

[mdo]

Breaking vertically across columns was addressed in #20654. As an aside, there's another bug though in Chrome as reported in #20925.